Saving a screen shot to the camera reel on android

Hi guys I've created an app in Flash Pro CC for iPhone and iPad and it works great, you can save an image of the screen to your camera reel fine. I've used the same code for the android version and when I tested it on our old HTC Wildfire it also worked fine. However now the app is live on Google Play a few users have left reviews saying the image dosnt save to their photo reel. Does anyone have any ideas why? Does it have something to do with the phones security settings not letting an app access the reel?

Heres a quick sample of the code:

import flash.media.CameraRoll;

var cameraRollcaddy:CameraRoll = new CameraRoll();

cameraRollcaddy.addEventListener(ErrorEvent.ERROR, onCrError);

cameraRollcaddy.addEventListener(Event.COMPLETE, onCrComplete);

var bitmapDatacaddy:BitmapData = new BitmapData(stage.stageWidth, stage.stageHeight = 640);

bitmapDatacaddy.draw(stage);

cameraRollcaddy.addBitmapData(bitmapDatacaddy);

}

else

{

trace("not supported.");

}

function onCrError(event:ErrorEvent):void

{

}

function onCrComplete(event:Event):void

{

}

Cheers Steve